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Averaged Behavior Model Of Current-Mode Buck Converters For Transient Power Noise Analysis, Anfeng Huang, Jingdong Sun, Hongseok Kim, Zhenxue Xu, Shuai Jin, Songping Wu, Zhiping Yang, Kelvin Qiu, Jun Fan, Chulsoon Hwang Jan 2023

Averaged Behavior Model Of Current-Mode Buck Converters For Transient Power Noise Analysis, Anfeng Huang, Jingdong Sun, Hongseok Kim, Zhenxue Xu, Shuai Jin, Songping Wu, Zhiping Yang, Kelvin Qiu, Jun Fan, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Accurate Evaluation and Simulation of Power Noise is Critical in the Development of Modern Electronic Devices. However, the Widely Used Target Impedance Fails to Predict the Low-Frequency Noise Generated in a Device Due to the Existence of the Dc–dc Converter, Whose Output Impedance Can Change under Different Loading Conditions. a Physical Circuit Model is Then Desired to Replicate the Behavior of a Voltage Regulator Module, and the Average Technique is an Efficient Method to Estimate the Noise of a Pulse Width-Modulated (PWM) Converter. with the Emergence of Converters with Adaptive On-Time (AOT) Controllers, More Complex Averaging Methods Are Required, But …

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Embeddable Soil Moisture Content Sensor Based On Open–End Microwave Coaxial Cable Resonator, Jing Guo, Yan Tang, Yongji Wu, Chen Zhu, Jie Huang Jan 2023

Embeddable Soil Moisture Content Sensor Based On Open–End Microwave Coaxial Cable Resonator, Jing Guo, Yan Tang, Yongji Wu, Chen Zhu, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In This Paper, We Propose and Demonstrate a Novel Corrosion-Resistant, Embeddable Open-End Coaxial Cable Soil Moisture Sensor. This Microwave Resonator is Constructed using Two Reflectors Along the Coaxial Line. the First Reflector is a Metal Post at the Signal Input End, Short-Circuiting the Inner Conductor to the Outer Conductor. the Second Reflector Comprises a Welded Metal Plate Parallel to the Open-End of the Coaxial Line, Maintaining a Fixed Gap. a Moisture-Sensitive Polyvinyl Alcohol (PVA) Film is Inserted into This Gap. the Resonance Frequency of the Open-End Coaxial Cable Resonator is Highly Dependent on the Fringe Capacitance, Which Varies with Soil …

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Electromagnetic Transmit Array With Optical Control For Beamforming, Wei Zhang, Javad Meiguni, Yin Sun, Muqi Ouyang, Xin Yan, Xu Wang, Reza Yazdani, Daryl G. Beetner, Donghyun Kim, David Pommerenke Jan 2023

Electromagnetic Transmit Array With Optical Control For Beamforming, Wei Zhang, Javad Meiguni, Yin Sun, Muqi Ouyang, Xin Yan, Xu Wang, Reza Yazdani, Daryl G. Beetner, Donghyun Kim, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

This Proof-Of-Concept Paper Demonstrates the Feasibility of using a Slide Projector to Steer the Beam of a Transmit Array by Adding Solar Cells and Varactor Diodes to Each Unit Cell. by Irradiating Each Solar Cell with the Light of Different Intensities from a Slide Projector, the Measured Phase of the Wave Transmitted by the 4x4 Transmit Array Shifts within 92° at 4.26 GHz, While the Variation in Magnitude is Measured within 4 DB. Different Light Configurations Are Identified Via a Searching Algorithm to Achieve Peak/null Beamforming in a Particular Direction. the Beam of the Prototypical 4x4 Transmit Array Can Be …

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An Extended Generalized Average Modeling Framework For Power Converters, Kartikeya Jayadurga Prasad Veeramraju, Jacob A. Mueller, Jonathan W. Kimball Jan 2023

An Extended Generalized Average Modeling Framework For Power Converters, Kartikeya Jayadurga Prasad Veeramraju, Jacob A. Mueller, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

The Generalized Averaged Modeling (GAM) technique is traditionally employed to capture the dynamic performance of power electronic converters. This paper proposes an improved version of it, named the Extended-GAM (EGAM) technique, which supports the multiplication of two Double Fourier Series (DFS) signals in the time domain. Multiplication of DFS signals in the time domain translates to the 2D-convolution of coefficients of the DFS terms of their equivalent Discrete Fourier Image (DFI) representations. Thus, the proposed EGAM technique, capable of capturing many harmonics present in the output of a power converter, effectively captures the dynamic behavior of power converters excited by …

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A Methodology For Predicting Improved Dipole Source Configurations From Near-Field Scan Data, Hossein Rezaei, Xin Yan, David J. Pommerenke, Daryl G. Beetner Jan 2023

A Methodology For Predicting Improved Dipole Source Configurations From Near-Field Scan Data, Hossein Rezaei, Xin Yan, David J. Pommerenke, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Equivalent sources found from near-electric and magnetic field scans are often used to predict and solve interference problems. While there are many ways to represent the source, the user lacks the ability to determine which of the many possible source configurations is more likely to represent the "true" source, and thus accurately represent field data outside the measurement area and in the presence of typical measurement errors. A methodology is proposed for estimating which of many possible dipole source representations of near-field scan data are likely to give better estimates of fields outside the measurement scan plane when utilizing imperfect …

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Multi-Layered Energy Management Framework For Extreme Fast Charging Stations Considering Demand Charges, Battery Degradation, And Forecast Uncertainties, Waqas Ur Rehman, Jonathan W. Kimball, Rui Bo Jan 2023

Multi-Layered Energy Management Framework For Extreme Fast Charging Stations Considering Demand Charges, Battery Degradation, And Forecast Uncertainties, Waqas Ur Rehman, Jonathan W. Kimball, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

To achieve a cost-effective and expeditious charging experience for extreme fast charging station (XFCS) owners and electric vehicle (EV) users, the optimal operation of XFCS is crucial. It is however challenging to simultaneously manage the profit from energy arbitrage, the cost of demand charges, and the degradation of a battery energy storage system (BESS) under uncertainties. This paper, therefore, proposes a multi-layered multi-time scale energy flow management framework for an XFCS by considering long- and short-term forecast uncertainties, monthly demand charges reduction, and BESS life degradation. In the proposed approach, an upper scheduling layer (USL) ensures the overall operation economy …

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Particulate Matter Detection In Mines Using 3d Light Detection And Ranging Technology, Zachary Osterwisch, Alexander Mauntel, Nathanael Nisbett, Dibbya Barua, Ahmad Alsharoa Jan 2023

Particulate Matter Detection In Mines Using 3d Light Detection And Ranging Technology, Zachary Osterwisch, Alexander Mauntel, Nathanael Nisbett, Dibbya Barua, Ahmad Alsharoa

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel portable prototype and self-contained Air Quality (AQ) monitoring device that utilizes Light Detection and Ranging (LiDAR) technology to take its measurements. The novel device aims to improve mining safety by collecting and analyzing the AQ inside mines and displaying the real-time conditions to personnel. The intent is to create a 3D map of the environment and display potentially hazardous Atmospheric Particulate Matter (APM). To achieve this goal, we prototype a portable, compact, and easy-to-operate system that utilizes LiDAR to detect APM. Then, we propose how the collected data can be used to calculate real-time AQ …

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Solving Electromagnetic Inverse Scattering Problems In Inhomogeneous Media By Deep Convolutional Encoder-Decoder Structure, Huan Huan Zhang, He Ming Yao, Lijun Jiang, Michael Ng Jan 2023

Solving Electromagnetic Inverse Scattering Problems In Inhomogeneous Media By Deep Convolutional Encoder-Decoder Structure, Huan Huan Zhang, He Ming Yao, Lijun Jiang, Michael Ng

Electrical and Computer Engineering Faculty Research & Creative Works

This communication proposes a novel deep learning (DL) approach to solve electromagnetic inverse scattering (EMIS) problems in inhomogeneous media. The conventional approaches for solving inhomogeneous EMIS problems generally have to consider inhomogeneous Green’s functions or conduct approximation operations to media, which inevitably introduces various challenges, including complex mathematical derivation, high computation cost, unavoidable nonlinearity, and even strong ill-posedness. To avoid these challenges, we propose a DL approach based on the complex-valued deep convolutional neural networks (DConvNets), which comprise the deep convolutional encoder–decoder (DCED) structure. Its training data are collected based on the simple synthetic dataset. While the scattered fields received …

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Nanosecond Peak Detect And Hold Circuit With Adjustable Dynamic Range, Gabriel Fellner, Lucas Speckbacher, Seyed Mostafa Mousavi, David Johannes Pommerenke, Satyajeet Shinde, Michael Hillstrom, Ram Chundru, Cheung Wei Lam Jan 2023

Nanosecond Peak Detect And Hold Circuit With Adjustable Dynamic Range, Gabriel Fellner, Lucas Speckbacher, Seyed Mostafa Mousavi, David Johannes Pommerenke, Satyajeet Shinde, Michael Hillstrom, Ram Chundru, Cheung Wei Lam

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents a novel peak detect and hold (PDH) circuit for the measurement of the peak voltage of electromagnetic-field probes. These probes are used to capture the fields generated by electrostatic discharge (ESD) events in nongrounded portable devices. Therefore, a circuit combining small size, low power consumption, and nanosecond operation is needed. A topology using a discrete bipolar transistor structure with operational transconductance amplifier (OTA) and common-base storage capacitor charge control optimally meets the requirements. The circuit performance is demonstrated for different bias point settings. The error between the captured value and the actual pulse peak value is shown …

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Observer-Based Model Predictive Control With Continuous Control Set For Single-Phase Rectifiers, Milad Dehghanzadeh, Rui Bo, Kamal Al-Haddad Jan 2023

Observer-Based Model Predictive Control With Continuous Control Set For Single-Phase Rectifiers, Milad Dehghanzadeh, Rui Bo, Kamal Al-Haddad

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a model predictive controller (MPC) is designed for a single-phase rectifier. The proposed MPC works with a continuous control set (CCS) that addresses variable switching issues in finite control set (FCS) MPCs. The observe-ability of the rectifier enables the design of a full-state observer to measure only output voltage in which the AC current of the rectifier is estimated. Both the proposed controller and observer are assessed with simulation studies and the results show the acceptable performance of the observer and CCS-MPC as well as good disturbance rejection in load and network parameter variations.

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Managing Reserve Deliverability Risk Of Integrated Electricity-Heat Systems In Day-Ahead Market: A Distributionally Robust Joint Chance Constrained Approach, Yang Chen, Jianxue Wang, Siyuan Wang, Rui Bo, Chenjia Gu, Qingtao Li Jan 2023

Managing Reserve Deliverability Risk Of Integrated Electricity-Heat Systems In Day-Ahead Market: A Distributionally Robust Joint Chance Constrained Approach, Yang Chen, Jianxue Wang, Siyuan Wang, Rui Bo, Chenjia Gu, Qingtao Li

Electrical and Computer Engineering Faculty Research & Creative Works

The integrated electricity and heat system (IEHS) is an emerging demand-side flexible resource for power systems. IEHS operators participating in electricity markets considering their capabilities in reserve provision will face the reserve deliverability risk due to the energy-limited storage nature of heat systems. To address this challenge and increase profitability, a distributionally robust joint chance-constrained mechanism with enhanced quantifications is adopted for the heating system and reserve deployment uncertainties. Detailed pipeline storage representation for thermal networks and integrated demand response are incorporated into this strategic participation model. A two-stage distributionally robust joint chance constrained program is then incorporated to effectively …

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Improved Quantification Of Defect Cross-Section For Active Microwave Thermography, Logan M. Wilcox, Kristen M. Donnell Jan 2023

Improved Quantification Of Defect Cross-Section For Active Microwave Thermography, Logan M. Wilcox, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Active microwave thermography (AMT) is an integrated nondestructive testing and evaluation (NDT&E) technique that features a microwave-based excitation and subsequent thermographic inspection via an infrared camera. AMT has been successfully employed in several industries including aerospace and civil for NDT&E inspections. Since the excitation is microwave-based, an antenna is used to irradiate the sample under test and hence the heating pattern will vary spatially (following the antenna pattern). This nonuniform thermal excitation may limit the ability of AMT to quantify defect cross-sections. Therefore, this work seeks to expand the capabilities of AMT by incorporating a post-processing technique to improve defect …

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Distributed Detection Over Blockchain-Aided Internet Of Things In The Presence Of Attacks, Yiming Jiang, Jiangfan Zhang Jan 2023

Distributed Detection Over Blockchain-Aided Internet Of Things In The Presence Of Attacks, Yiming Jiang, Jiangfan Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

Distributed detection over a blockchain-aided Internet of Things (BIoT) network in the presence of attacks is considered, where the integrated blockchain is employed to secure data exchanges over the BIoT as well as data storage at the agents of the BIoT. We consider a general adversary model where attackers jointly exploit the vulnerability of IoT devices and that of the blockchain employed in the BIoT. The optimal attacking strategy which minimizes the Kullback-Leibler divergence is pursued. It can be shown that this optimization problem is nonconvex, and hence it is generally intractable to find the globally optimal solution to such …

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Transformer Leakage Inductance Design Methodology, Angshuman Sharma, Jonathan W. Kimball Jan 2023

Transformer Leakage Inductance Design Methodology, Angshuman Sharma, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

The leakage inductance exhibited by a transformer depends on its winding geometry, which generally involves the selection of several key design parameters in addition to the winding structure and the interleaving configuration. With few resources explaining the effects of these design choices on the observed leakage inductance, numerous trial-and-error iterations become necessary to realize the desired leakage inductance. This paper explores more than a hundred winding geometries feasible in a 2- winding transformer comprising the same magnetic core, number of turns, and wire gauge, and finds the leakage inductance for each unique design using 2-D finite element method (FEM) simulations …

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Modeling And Mitigation Of Radio Frequency Interference For Wireless Devices, Chulsoon Hwang, Jun Fan Jan 2023

Modeling And Mitigation Of Radio Frequency Interference For Wireless Devices, Chulsoon Hwang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

This article reviews the electromagnetic framework used to model radio frequency interference (RFI) and the resulting development of mitigation methods. With the rise of IoT devices, wireless devices in which RF antennas are integrated with high-performance digital systems in small form factors suffer from electromagnetic interference, known as RF interference or RF desensitization. The simple yet rigorous framework can be used for a systematic RFI-aware design, saving time and effort for trial-and-error troubleshooting.

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Multi-Point Optical Fiber Fabry-Perot Curvature Sensor Based On Microwave Photonics, Chen Zhu, Ruimin Jie, Osamah Alsalman, Hongkun Zheng, Wassana Naku, Bo Liu, Lingmei Ma Jan 2023

Multi-Point Optical Fiber Fabry-Perot Curvature Sensor Based On Microwave Photonics, Chen Zhu, Ruimin Jie, Osamah Alsalman, Hongkun Zheng, Wassana Naku, Bo Liu, Lingmei Ma

Electrical and Computer Engineering Faculty Research & Creative Works

This article reports a multi-point curvature sensor system based on multiplexed optical fiber Fabry-Perot interferometric (FPI) sensor devices and a microwave photonics interrogation technique. The FPI sensor is fabricated with the assistance of a capillary tube, where a short section of the capillary is sandwiched between two single-mode fibers, forming the airgap Fabry-Perot cavity. Bending of the FPI device leads to changes in the fringe contrast of its reflection spectrum. Based on the microwave photonics filtering technique, variations of the fringe contrast are encoded into the changes in the peak magnitude of the passband in the frequency response of the …

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Development Of A Matlab-Based Structural Analysis Toolbox For Sensor Placement In A Multi-Domain Physical System, Arnold A. Fernandes, Kartikeya J.P. Veeramraju, Jonathan W. Kimball Jan 2023

Development Of A Matlab-Based Structural Analysis Toolbox For Sensor Placement In A Multi-Domain Physical System, Arnold A. Fernandes, Kartikeya J.P. Veeramraju, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

This paper discusses a Bond Graph (BG) Structural Analysis Toolbox developed in MATLAB® (MATSAT) that performs causal analysis on the BG and assists the user in the sensor selection process for a multi-domain physical system. MATSAT contains modules for performing the Sequential Causality Assignment Procedure (SCAP) and Causal Path Search (CaPS). The modules can be combined to check for structural properties such as structural observability (SO) for any sensor set. The working of MATSAT is shown for standard systems. Verification of SCAP, CaPS, and necessary and sufficient SO conditions is shown.

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Continual Reinforcement Learning Formulation For Zero-Sum Game-Based Constrained Optimal Tracking, Behzad Farzanegan, Sarangapani Jagannathan Jan 2023

Continual Reinforcement Learning Formulation For Zero-Sum Game-Based Constrained Optimal Tracking, Behzad Farzanegan, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This study provides a novel reinforcement learning-based optimal tracking control of partially uncertain nonlinear discrete-time (DT) systems with state constraints using zero-sum game (ZSG) formulation. To address optimal tracking, a novel augmented system consisting of tracking error and its integral value, along with an uncertain desired trajectory, is constructed. A barrier function (BF) with a tradeoff factor is incorporated into the cost function to keep the state trajectories to remain within a compact set and to balance safety with optimality. Next, by using the modified value functional, the ZSG formulation is introduced wherein an actor–critic neural network (NN) framework is …

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Optimal Tracking Of Nonlinear Discrete-Time Systems Using Zero-Sum Game Formulation And Hybrid Learning, Behzad Farzanegan, S. (Sarangapani) Jagannathan Jan 2023

Optimal Tracking Of Nonlinear Discrete-Time Systems Using Zero-Sum Game Formulation And Hybrid Learning, Behzad Farzanegan, S. (Sarangapani) Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel hybrid learning-based optimal tracking method to address zero-sum game problems for partially uncertain nonlinear discrete-time systems. An augmented system and its associated discounted cost function are defined to address optimal tracking. Three multi-layer neural networks (NNs) are utilized to approximate the optimal control and the worst-case disturbance inputs, and the value function. The critic weights are tuned using the hybrid technique, whose weights are updated once at the sampling instants and in an iterative manner over finite times within the sampling instants. The proposed hybrid technique helps accelerate the convergence of the approximated value functional …

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Virtual Synchronous Generator Control Using Twin Delayed Deep Deterministic Policy Gradient Method, Oroghene Oboreh-Snapps, Buxin She, Shah Fahad, Haotian Chen, Jonathan W. Kimball, Fangxing Li, Hantao Cui, Rui Bo Jan 2023

Virtual Synchronous Generator Control Using Twin Delayed Deep Deterministic Policy Gradient Method, Oroghene Oboreh-Snapps, Buxin She, Shah Fahad, Haotian Chen, Jonathan W. Kimball, Fangxing Li, Hantao Cui, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a data-driven approach that adaptively tunes the parameters of a virtual synchronous generator to achieve optimal frequency response against disturbances. In the proposed approach, the control variables, namely, the virtual moment of inertia and damping factor, are transformed into actions of a reinforcement learning agent. Different from the state-of-the-art methods, the proposed study introduces the settling time parameter as one of the observations in addition to the frequency and rate of change of frequency (RoCoF). In the reward function, preset indices are considered to simultaneously ensure bounded frequency deviation, low RoCoF, fast response, and quick settling time. …

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Aerial Lidar-Based 3d Object Detection And Tracking For Traffic Monitoring, Baya Cherif, Hakim Ghazzai, Ahmad Alsharoa, Hichem Besbes, Yehia Massoud Jan 2023

Aerial Lidar-Based 3d Object Detection And Tracking For Traffic Monitoring, Baya Cherif, Hakim Ghazzai, Ahmad Alsharoa, Hichem Besbes, Yehia Massoud

Electrical and Computer Engineering Faculty Research & Creative Works

The proliferation of Light Detection and Ranging (LiDAR) technology in the automotive industry has quickly promoted its use in many emerging areas in smart cities and internet-of-things. Compared to other sensors, like cameras and radars, LiDAR provides up to 64 scanning channels, vertical and horizontal field of view, high precision, high detection range, and great performance under poor weather conditions. In this paper, we propose a novel aerial traffic monitoring solution based on Light Detection and Ranging (LiDAR) technology. By equipping unmanned aerial vehicles (UAVs) with a LiDAR sensor, we generate 3D point cloud data that can be used for …

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Performance Evaluation Of Composite Sandwich Structures With Additively Manufactured Aluminum Honeycomb Cores With Increased Bonding Surface Area, M. Rangapuram, S. K. Dasari, Joseph William Newkirk, K. Chandrashekhara, H. Misak, P. R. Toivonen, D. Klenosky, T. Unruh, J. Sam Jan 2023

Performance Evaluation Of Composite Sandwich Structures With Additively Manufactured Aluminum Honeycomb Cores With Increased Bonding Surface Area, M. Rangapuram, S. K. Dasari, Joseph William Newkirk, K. Chandrashekhara, H. Misak, P. R. Toivonen, D. Klenosky, T. Unruh, J. Sam

Materials Science and Engineering Faculty Research & Creative Works

Modern aerostructures, including wings and fuselages, increasingly feature sandwich structures due to their high-energy absorption, low weight, and high flexural stiffness. The face sheet of these sandwich structures are typically thin composite laminates with interior honeycombs made of Nomex or aluminum. Standard cores are structurally efficient, but their design cannot be varied throughout the structure. With additive manufacturing (AM) technology, these core geometries can be altered to meet the design requirements that are not met in standard honeycomb cores. This study used a modified aluminum honeycomb core, with increased surface area on the top and bottom, as the core material …

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Final-Stage Densification Kinetics Of Direct Current–Sintered Zrb2, Austin D. Stanfield, Steven M. Smith, Suzana Filipović, Nina Obradović, Vladimir Buljak, Gregory E. Hilmas, William Fahrenholtz Jan 2023

Final-Stage Densification Kinetics Of Direct Current–Sintered Zrb2, Austin D. Stanfield, Steven M. Smith, Suzana Filipović, Nina Obradović, Vladimir Buljak, Gregory E. Hilmas, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to …

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Antioxidant Theranostic Copolymer-Mediated Reduction In Oxidative Stress Following Traumatic Brain Injury Improves Outcome In A Mouse Model, Aria W. Tarudji, Connor C. Gee, Hunter A. Miller, Rylie Steffen, Evan T. Curtis, Aaron M. Priester, Anthony J. Convertine, Forrest M. Kievit Jan 2023

Antioxidant Theranostic Copolymer-Mediated Reduction In Oxidative Stress Following Traumatic Brain Injury Improves Outcome In A Mouse Model, Aria W. Tarudji, Connor C. Gee, Hunter A. Miller, Rylie Steffen, Evan T. Curtis, Aaron M. Priester, Anthony J. Convertine, Forrest M. Kievit

Materials Science and Engineering Faculty Research & Creative Works

Following a traumatic brain injury (TBI), excess reactive oxygen species (ROS) and lipid peroxidation products (LPOx) are generated and lead to secondary injury beyond the primary insult. A major limitation of current treatments is poor target engagement, which has prevented success in clinical trials. Thus, nanoparticle-based treatments have received recent attention because of their ability to increase accumulation and retention in damaged brain. Theranostic neuroprotective copolymers (NPC3) containing thiol functional groups can neutralize ROS and LPOx. Immediate administration of NPC3 following injury in a controlled cortical impact (CCI) mouse model provides a therapeutic window in reducing ROS levels at 2.08–20.83 …

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Morphological And Structural Characterization Of Mgal2o4 Spinel, Nina Obradović, Suzana Filipović, William Fahrenholtz, Bojan A. Marinkovic, Jelena Rogan, Steva Lević, Antonije Đorđević, Vladimir B. Pavlović Jan 2023

Morphological And Structural Characterization Of Mgal2o4 Spinel, Nina Obradović, Suzana Filipović, William Fahrenholtz, Bojan A. Marinkovic, Jelena Rogan, Steva Lević, Antonije Đorđević, Vladimir B. Pavlović

Materials Science and Engineering Faculty Research & Creative Works

Magnesium aluminate has the spinel structure along with good mechanical, chemical, and thermal properties. Magnesium aluminate has a wide range of applications including refractory ceramics, optically transparent ceramic windows, and armors. Its low dielectric permeability and low loss tangent enable its applications for integrated electronic devices, as well. In this paper, MgO and Al2O3 powders were mixed in a one-to-one molar ratio and calcined at temperatures ranging from 1500 to 1800o C to produce phase pure spinel. Thereafter, pellets were crushed and treated in a planetary ball mill for 60 min to obtain a fine powder. All …

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Effect Of Mechanical Activation On Carbothermal Synthesis And Densification Of Zrc, Nina Obradović, Lun Feng, Suzana Filipović, Miljana Mirković, Darko Kosanović, Jelena Rogan, William Fahrenholtz Jan 2023

Effect Of Mechanical Activation On Carbothermal Synthesis And Densification Of Zrc, Nina Obradović, Lun Feng, Suzana Filipović, Miljana Mirković, Darko Kosanović, Jelena Rogan, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled …

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Molecular Mechanism Study On The Effect Of Nonionic Surfactants With Different Degrees Of Ethoxylation On The Wettability Of Anthracite, Xuanlai Chen, Guochao Yan, You Zhou, Guang Xu, Xuyang Bai, Jiajun Li Jan 2023

Molecular Mechanism Study On The Effect Of Nonionic Surfactants With Different Degrees Of Ethoxylation On The Wettability Of Anthracite, Xuanlai Chen, Guochao Yan, You Zhou, Guang Xu, Xuyang Bai, Jiajun Li

Mining Engineering Faculty Research & Creative Works

A serious risk to the production safety of coal mines is coal dust. The wettability of coal may be successfully changed by adding surfactants to water. However, the creation of very effective dust suppressants is constrained by the lack of knowledge about the microscopic interaction mechanism between coal dust and surfactants. In this investigation, we explained macroscopic experimental phenomena from a molecular perspective. The lauryl polyoxyethylene ethers (C12 (EO)n, n = 7,15,23) were selected. The macromolecular model of anthracite with 55 different components was constructed. Surface tension experiments and hydrophilic lipophilic balance (HLB) calculations showed that the ability of surface …

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Molecular Mechanism Study On The Effect Of Nonionic Surfactants With Different Degrees Of Ethoxylation On The Wettability Of Anthracite, Xuanlai Chen, Guochao Yan, You Zhou, Guang Xu, Xuyang Bai, Jiajun Li Jan 2023

Molecular Mechanism Study On The Effect Of Nonionic Surfactants With Different Degrees Of Ethoxylation On The Wettability Of Anthracite, Xuanlai Chen, Guochao Yan, You Zhou, Guang Xu, Xuyang Bai, Jiajun Li

Mining Engineering Faculty Research & Creative Works

A serious risk to the production safety of coal mines is coal dust. The wettability of coal may be successfully changed by adding surfactants to water. However, the creation of very effective dust suppressants is constrained by the lack of knowledge about the microscopic interaction mechanism between coal dust and surfactants. In this investigation, we explained macroscopic experimental phenomena from a molecular perspective. The lauryl polyoxyethylene ethers (C12 (EO)n, n = 7,15,23) were selected. The macromolecular model of anthracite with 55 different components was constructed. Surface tension experiments and hydrophilic lipophilic balance (HLB) calculations showed that the …

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Highly Sensitive Humidity Sensor Based On Optical Fiber Fabry-Perot Interferometer, Chen Zhu, Jie Huang Jan 2023

Highly Sensitive Humidity Sensor Based On Optical Fiber Fabry-Perot Interferometer, Chen Zhu, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

An ultra-sensitive optical fiber humidity sensor based on an extrinsic Fabry-Perot interferometer is proposed and experimentally demonstrated in this paper. the Fabry-Perot cavity is constructed by a section of humidity-sensitive metal-paper coil and an optical fiber end face. Taking advantage of the hydrophilicity of the metal-paper coil, the cavity length of the Fabry-Perot cavity varies with humidity due to the deflection of the metal-paper section. the fabricated sensor shows a linear response to relative humidity (RH) spanning from 50%RH to 73%RH. More prominently, an ultra-high sensitivity of 32.5 μm%RH (change in cavity length/change in RH) or 63.5 nm%RH (wavelength shift/change …

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Bidirectional Asymmetric Clllc Resonant Dc-Dc Converter For Onboard Electric Vehicle Chargers, Angshuman Sharma, Alvaro Cardoza, Kartikeya J.P. Veeramraju, Oroghene Oboreh-Snapps, Jonathan W. Kimball Jan 2023

Bidirectional Asymmetric Clllc Resonant Dc-Dc Converter For Onboard Electric Vehicle Chargers, Angshuman Sharma, Alvaro Cardoza, Kartikeya J.P. Veeramraju, Oroghene Oboreh-Snapps, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

Bidirectional CLLLC resonant dc-dc converters with an asymmetric tank can narrow the switching frequency bandwidth required to meet the asymmetric voltage gains in the two directions of power flow. Consequently, higher power density and efficiency may be feasible. in this paper, a CLLLC resonant converter with asymmetric primary and secondary capacitances is investigated for charging and discharging the next-generation 900 V traction battery of an electric vehicle. First, a new voltage gain equation is formulated using the First Harmonic Approximation. Then, the proposed gain equation is used to design the asymmetric resonant tank. the effects of asymmetric capacitances on the …

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